I personally wouldn't do it for the simple fact Z400's make crap for power.

 

Crap for power???? well the piped z400s ive seen sure do DAMN good for being a 400.

 

yeah, can you imagine the power a z would make if it was a 660? The z does real good I think. I don't like what I've heard of the 03s though, then again I've heard bad things about the 01 raptor too. They're both first production years. If it was an 05 or 06 z you'd be crazy not to. But I guess all it would take to make it one would be some frame gusseting, carb,clutch,suspension-how much of this is included in the mods? The 03 z made like 30 hp and the 06 makes 36.6 May not seem like that big of a difference, but when your dealing with so little in the first place that comes out to a 20% increase